The vfx highlight was a photoreal CG bat that makes an appearance at the film's end.

But the centerpiece is a CG-animated bat that figures prominently in the story. "Steven had this idea that the bat takes a piece of banana in close-up and moves on into the interior of a pig farm in Hong Kong, where it drops a piece of it and then pigs come on over and start eating it," Smith suggests.

The computer animation was done at Method's Vancouver office. They had previously done a bat for Tropic Thunder. But this one was close up and totally photoreal. They shot the plates early on in the schedule and were able to design and animate the bat right away.

"We fashioned it after a fruit bat from Southeast Asia," Smith continues. "I found a taxidermy bat that was similar. We had some live reference of a dehydrated bat to look at the transparency and translucency of the wings. The animators then looked around for good reference for how they moved."

But what Soderbergh was after was something very gnarly-looking that viewers would find disturbing. "He liked the concept and let us run with the bat and then when we got notes from him later. Its nose is real pointed and very [ugly] and just makes you [wince]."

In the first shot of the sequence, the bat lands on the bananas. From that point on, we push in tighter and see that he's eating one. He breaks a piece off and flies away. "We tried to get the head movements right. And they did a really nice job of getting quick gestures and movements. Flying was the other challenge to make sure the bat wings had a natural weight. They're pretty light. We went through a lot of iterations to get the flitter. They zig-zag and move erratically. There were initially five shots and then another one was added later. Part of the backstory was corporations involved in deforestation in the region. A bulldozer comes through and hits a palm tree and a group of bats flies away. Their environment gets disrupted and part of the unintended consequence is the spread of the virus.We used <Maya> and mental ray and composited in Nuke.

"The reaction we first got from him was that he liked how it made you feel uneasy. When it came to giving lighting notes, he'd say, 'I want you to put the light a little bit different on the bat so we have more side lighting. It really helps that he's the cinematographer."

Bill Desowitz is former senior editor of AWN and editor of VFXWorld. He has a new blog, Immersed in Movies (www.billdesowitz.com), and is currently writing a book about the evolution of James Bond from Connery to Craig, scheduled for publication next year, which is the 50th anniversary of the franchise.